JP2002265801A - Powder molding thermoplastic resin composition improved in moldability and molded product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder molding thermoplastic resin composition good in releasability from a mold and excellent in moldability, and to provide a molded product having no pinhole on its surface and excellent in scratch resistance and adhesion. SOLUTION: This powder molding thermoplastic resin composition is composed of powder such as a urethane-based thermoplastic elastomer composition or an olefin-based thermoplastic elastomer composition as the main material and a resin selected from at least one of the same kind resin of the main material powder or resins having good compatibility with the main material powder as the principal ingredient, compounded >=2 but <30 pts.mass silicone oil per 100 pts.mass resin component and compounded with a resin composition having a smaller mean particle diameter than that of the main material powder as an auxiliary material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition for powder molding having improved moldability and a molded article using the same, and more particularly to a urethane-based thermoplastic elastomer composition, an olefin-based thermoplastic elastomer. The main material powder is a thermoplastic resin composition powder such as a composition, and the main material powder is a mixture of the same kind of resin as the main material or a resin having good compatibility with the main material mixed with silicone oil and pulverized as an auxiliary material. By adding and mixing to the body, the thermoplastic resin composition for powder molding has excellent moldability without using an external release agent, and has no pinholes on the surface, good scratch resistance, and adhesion It relates to a molded article having excellent properties.

[0002]

2. Description of the Related Art As a powder molding method using a soft powder material, a slash molding method using a soft vinyl chloride resin powder has been widely adopted for the skin of automobile interior parts such as instrument panels, console boxes and door trims. I have. This is a soft touch, and can be provided with leather grain and stitches, and has good design properties such as a large degree of freedom in design.

[0003] Unlike other molding methods such as injection molding and compression molding, this molding method does not apply a shaping pressure. Therefore, in order to uniformly adhere a powder material to a mold having a complicated shape at the time of molding, powder molding is performed. It is necessary to have excellent fluidity, and the powder attached to the mold melts and flows even under no pressure to form a film. Has become. Furthermore, it is necessary that the molded skin can be released from the mold more easily by cooling the mold,
When laminating a molded sheet with another material, it is necessary to be able to easily adhere.

[0004] The properties required for these powder molding materials can be easily achieved by adjusting the compounding amount of the plasticizer if soft PVC is used, but technical problems are encountered with other thermoplastic elastomers. Many. As one method for improving this, Japanese Patent Application Laid-Open No. 7-82433 discloses that a polypropylene resin and a specific styrene-based thermoplastic elastomer have a weight ratio of 70/70.
It has been proposed to pulverize and use a mixture of 30 to 30/70. Here, the styrene-based thermoplastic elastomer is a styrene / ethylene / butylene / styrene block copolymer having a styrene content of 20% by weight or less, a styrene / ethylene propylene / styrene block copolymer having a styrene content of 20% by weight or less, and a styrene content of 20% by weight. % Or less of a hydrogenated styrene-butadiene rubber, and has a good compatibility with a polypropylene resin and is a composition suitable for powder molding.

[0005]

Generally, when powders such as urethane-based thermoplastic elastomer compositions and olefin-based thermoplastic elastomer compositions are used as powder molding materials, the molding fluid is insufficient due to insufficient melt flowability. Mold temperature is 22
A temperature of 0 ° C. or higher is required. Under such a high temperature condition, a release agent applied to a mold, that is, an external release agent is thermally decomposed and cannot be used. Further, when the internal release agent is added to the main composition at the time of polymerization or kneading, the effect is small unless the amount of the internal release agent is increased relative to the resin composition of the main material.
In addition, when added in a large amount, there is a drawback that the physical properties of the molded body are reduced and adhesion becomes difficult. Further, since the surface tension of the molten resin is large, pinholes are easily generated on the surface, and there is a problem that the molded article surface is not slippery and thus has poor scratch resistance.

The present invention has been made to solve such problems, and has excellent moldability without applying an external release agent to a mold or blending an internal release agent into a main resin composition. It is also an object of the present invention to provide a thermoplastic resin composition for powder molding, which has good demolding property of the molded article, and a molded article having no pinholes on the surface, having good surface scratch resistance, and excellent adhesion. And

[0007]

That is, according to the invention of claim 1 of the present application, a thermoplastic resin composition for powder molding mainly comprising a thermoplastic resin composition powder is the same as the main material powder. The main component is a resin selected from at least one of a type of resin or a resin having good compatibility with the main material powder.
A powdery resin composition containing 2 parts by mass or more and less than 30 parts by mass of silicone oil with respect to parts by mass, the resin composition having an average particle size less than the average particle size of the main material powder. As a thermoplastic resin composition for powder molding mixed with a main material powder.

According to the second aspect of the present invention, in the thermoplastic resin composition for powder molding according to the first aspect, the auxiliary material is used in an amount of 0.1 parts by mass or more based on 100 parts by mass of the main material powder. 2
It is a thermoplastic resin composition for powder molding compounded in a proportion of less than 0 parts by mass.

According to the invention described in claim 3 of the present application, claim 1
Or in the thermoplastic resin composition for powder molding according to 2,
The melting point of the resin as the main component of the auxiliary material is a thermoplastic resin composition for powder molding having a melting point or softening point of the resin of the main material powder of 100 ° C. or higher, and by using the resin. A molded body with few surface pinholes can be obtained.

According to the invention described in claim 4 of the present application, claim 1
4. The thermoplastic resin composition for powder molding according to any one of (1) to (3), wherein an average primary amount is 100 parts by mass of the thermoplastic resin composition for powder molding obtained by mixing the main material powder and the auxiliary material. It is a thermoplastic resin composition for powder molding in which an inorganic or organic fine powder having a particle size of 1 μm or less is blended in an amount of 0.02 parts by mass or more and less than 5.0 parts by mass. By doing so, air can easily escape from the surface of the molded body during molding, and a molded body with few surface pinholes can be obtained.

According to the invention described in claim 5 of the present application, claim 1
5. The thermoplastic resin composition for powder molding according to any one of Items 1 to 4, wherein the main material powder is a thermoplastic resin composition for powder molding, which is a thermoplastic elastomer composition.

According to the invention described in claim 6 of the present application, claim 5
In the thermoplastic resin composition for powder molding described in the above, the main material powder is a urethane-based thermoplastic elastomer composition, the main component of the auxiliary material is selected from at least one of 12 nylon, thermoplastic urethane It is a thermoplastic resin composition for powder molding, and the main material powder and the auxiliary material are well compatible with each other, so that a molded article having good physical properties and adhesiveness can be obtained.

According to the invention described in claim 7 of the present application, claim 5
In the thermoplastic resin composition for powder molding according to the above, the main material powder is an olefin-based thermoplastic elastomer composition, the main component of the auxiliary material is polypropylene, the thermoplastic elastomer composition of polypropylene is a matrix It is a thermoplastic resin composition for powder molding selected from at least one. Since the main material powder and the auxiliary material are well compatible with each other, a molded article having good physical properties and adhesiveness can be obtained.

According to the invention described in claim 8 of the present application, claim 7
The thermoplastic elastomer composition according to claim 1, wherein the olefin-based thermoplastic elastomer composition is a thermoplastic elastomer composition containing at least a polypropylene resin, a hydrogenated styrene-butadiene rubber, and an ethylene / α-olefin block copolymer. It is a thermoplastic resin composition for use.

According to the invention described in claim 9 of the present application, claim 1
A molded article obtained by powder molding of the thermoplastic resin composition for powder molding according to any one of Items 1 to 8, which has no pinholes on its surface, has good surface lubricity, has good scratch resistance, and has excellent adhesiveness. A molded article is obtained.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As the resin of the main material powder used in the slush molding of the present invention, a thermoplastic resin composition can be mentioned. Among them, a thermoplastic resin composition such as an olefin-based thermoplastic elastomer composition or a urethane-based thermoplastic elastomer composition is preferred. A plastic elastomer composition is generally used, and these non-PVC materials are preferable in terms of environment and safety. Examples of the olefin-based thermoplastic elastomer composition include, for example, a thermoplastic elastomer composition comprising a polypropylene resin, a hydrogenated styrene-butadiene rubber, and an ethylene / α-olefin block copolymer described in JP-A-9-52990. When the thermoplastic elastomer composition to which the peroxide is added is used, the thermoplastic elastomer composition has a melt fluidity required for powder molding.

As the urethane-based thermoplastic elastomer composition, for example, a urethane-based thermoplastic elastomer composition for powder molding obtained from polyester diol, short-chain diol and organic diisocyanate described in JP-A-07-316254 may be used. it can.

When a thermoplastic elastomer composition such as a urethane-based thermoplastic elastomer composition or an olefin-based thermoplastic elastomer composition is used as a main material of a powder molding material, these resin compositions have a melt fluidity. Is low, the temperature of the molding die needs to be 220 ° C. or higher. Under such high temperature conditions, the external release agent applied to the die is thermally decomposed and cannot be used. When the internal release agent is added to the main composition at the time of polymerization or kneading, the effect is small unless the amount of addition to the main composition is increased, and if it is added excessively, the physical properties of the molded body are reduced and adhesion is difficult. There are disadvantages. In addition, since the surface tension of the molten resin is large, there is a problem that a pinhole is formed on the surface.

The present invention provides a means for solving the above problems.
A resin composition obtained by blending silicone oil with a resin of the same type as the main material powder or having good compatibility with the main material powder for the purpose of improving mold release properties and preventing the occurrence of pinholes in powder molding. Is added as an auxiliary material.

As a resin used for the auxiliary material, it is essential to use a resin of the same type as the main material powder or a resin having good compatibility with the main material powder as a main component. When the thermoplastic elastomer composition (TPU) is used, the main component resin of the auxiliary material is a thermoplastic urethane, for example, TPU Desmopan manufactured by Sumitomo Bayer Corporation. Examples of the resin having good compatibility with the main material powder include a polyamide resin, and particularly preferably a 12-nylon resin having a low melting point,
Specifically, the MFR is 100 g / 10 min (JISK721
0), a Vesamelt 432DR manufactured by Daicel Huels with a melting point of 110 ° C.

When the main material powder is an olefin-based thermoplastic elastomer, the resin used for the auxiliary material may be low-melting-point polypropylene, and specifically, has an MFR of 1
There is a low melting point polypropylene CS3650 manufactured by Chisso with a melting point of 137 ° C. at 6 g / min. It is also preferable to use a high melt fluidity polypropylene, for example, having an MFR of 400 g / 10
HH4 manufactured by Montell Corporation (JIS K7210)
41 can be exemplified. In order to improve the melt fluidity of the polypropylene used for the auxiliary material, the polypropylene can be decomposed by peroxide to reduce the molecular weight before use. Further, in order to impart appropriate flexibility to the molded article, it is also possible to use a blended or alloyed elastomer component.

Further, as a resin having good compatibility with the olefin-based thermoplastic elastomer composition, propylene and α-
Examples include olefin copolymers, block copolymers or graft polymers of propylene and other monomers, block copolymers or graft polymers of olefins and other monomers, polyurethanes or polyamides obtained by graft polymerization of olefins, and 12 nylon.

The melting point of the resin used for the auxiliary material is desirably 100 ° C. or higher and not higher than the melting point or softening point of the main powder. By setting the temperature within this range, the auxiliary material is melted before the main material powder to cover the mold, and there is an effect of improving the releasability of the molded body. When the temperature is lower than 100 ° C., since there is an operation of returning the powder that has not been thermally fused to the mold to the powder supply box in the powder molding, the molding is repeatedly performed or the molding is performed in summer. In this case, the temperature of the powder in the powder supply box may increase, and the auxiliary material may be melted to cause agglomeration of the powder. In addition, it is preferable that the melting point of the resin used for the auxiliary material is 100 ° C. or more, since heat resistance of 100 ° C. or more is required as a general specification of the skin molded body used for the instrument panel. On the other hand, when the auxiliary material is higher than the melting point or softening point of the main material powder, the auxiliary material cannot be melted unless the molding temperature is set to a temperature higher than 220 ° C., and the effect of improving the releasability is reduced. Can't expect.

The auxiliary material also has an effect of preventing occurrence of underfill and pinholes on the surface of the compact. Generally, the thermoplastic resin composition powder as a main material has a particle size of about 100 to 800 μm. It cannot cope with a complicated shape and cannot enter into the fine irregularities of the mold, resulting in pinholes and underfill. In order to enter the pinhole, that is, the gap between the mold and the main material powder, the auxiliary material needs to have a smaller particle size than the main material powder. That is, the average particle size of the auxiliary material is preferably smaller than the average particle size of the thermoplastic resin composition powder as the main material.

In the present invention, the silicone oil to be melt-kneaded with the auxiliary material preferably has a high viscosity, more specifically, a viscosity of 1000 cs or more. The low-viscosity product has a small molecular weight and easily causes bleed-out to the surface of the molded skin, and inhibits the adhesiveness. It is possible to mix the silicone oil alone, but preferably, a master batch pellet in which about 50% of a high-viscosity silicone oil is previously kneaded with a resin is easy to handle. As the resin, a polypropylene resin or a low-density polyethylene resin is used, and as a master batch pellet using the resin, a silicone oil master batch BY27-001 or BY27-00 manufactured by Toray Dow Silicone Co., Ltd.
There are two.

The amount of the silicone oil to be added must be adjusted so as to be at least 2 parts by mass and less than 30 parts by mass with respect to 100 parts by mass of the resin component of the auxiliary material. Is low, and when the amount is 30 parts by mass or more, a decrease in physical properties and a decrease in adhesiveness of the molded article are observed. The effect of silicone oil improves the mold release effect between the mold and the molded body, and also lowers the surface tension of the molten resin, which has the effect of promoting the wetting flow of the resin under no pressure. There is also an effect of improving the scratch resistance in order to improve the lubricity of the surface of the molded sheet.

The ratio of silicone oil to the thermoplastic resin composition for powder molding in which the main material powder and the auxiliary material are mixed is as follows: 100 parts by mass of the thermoplastic resin composition for powder molding, silicone oil Is preferably adjusted to be contained in an amount of 0.0005 to 0.1 part by mass.

Further, by mixing an inorganic or organic fine powder having an average primary particle size of 1 μm or less into a thermoplastic resin composition for powder molding in which a main material powder and an auxiliary material are mixed, Since the air between the resin powders is easily interposed between the resin powders during molding, the molded product having few surface pinholes can be obtained. Examples of the inorganic fine powder include silica and light calcium carbonate, specifically, soft calcium carbonate MSK-C manufactured by Maruo Calcium Co., Ltd. As the organic fine powder, a resin fine powder obtained by drying an emulsion-polymerized or suspension-polymerized MMA resin or a styrene resin to form a powder can be used.

The addition amount of the inorganic or organic fine powder is 0.02
The amount is preferably from not less than 5.0 parts by mass to less than 0.02 parts by mass.
If it is 0 mass or more, fine powder is present as foreign matter, which causes a decrease in the tensile properties of the molded body.

The method of adding the auxiliary material and further the inorganic or organic fine powder to the thermoplastic resin composition powder as the main material is not particularly limited, but the dry method is carried out using a tumbler or a Henschel mixer. It can be used by blending.

Next, powder molding is performed using the thermoplastic resin composition for powder molding in which the above powders are mixed. In this molding, the resin powder is dropped by gravity into a mold heated to a temperature higher than the melting point or softening point of the composition used for the outer skin, and after a certain period of time, the mold is inverted and excess powder is collected in a collection box. Collect. The composition adheres as a layer to the surface of the mold, and melts over time to form a skin molded article having a skin layer having a thickness of 0.3 to 1.0 mm.

It should be noted that the above example is merely an example, and it is of course possible to laminate two or more layers of the skin. In the case of laminating two or more layers, the composition to be used for the inner layer is then dropped onto the above-mentioned skin layer and charged, and after a certain period of time, the mold is inverted and the excess composition is collected in a collection box. The layer adhering to the skin layer melts over time to form an inner layer having a thickness of 0.1 to 0.5 mm. Then, the mold is cooled and released, and this is repeated according to the number of layers.

The inner layer of the skin material is not particularly limited, and a publicly known one can be used. However, when a urethane thermoplastic elastomer is selected for the outer layer, generally used urethane foam is desirable. This is because the use of a material having a similar composition to the outer layer and the inner layer is advantageous in terms of recycling. For the same reason, when an olefin-based thermoplastic elastomer is selected for the outer layer,
The inner layer is desirably a thermoplastic elastomer composition containing at least a polypropylene resin, a hydrogenated styrene-butadiene rubber, a process oil, an elastomer having excellent oil absorbing ability, and a foaming agent.

The molded skin product obtained by the above powder molding is mounted on one mold so that the outer layer touches the mold surface. Then, a core material made of a synthetic resin such as polypropylene, ABS, or polystyrene is provided in the other mold, and a foaming solution such as polyurethane is cast between them to form a foamed layer, thereby forming a molded body with a skin. Form.

[0035]

Next, the present invention will be described in more detail with reference to specific examples. In Examples 1 to 7 and Comparative Examples 1 to 4, a urethane-based thermoplastic elastomer composition powder (average particle size of 167 μm) produced by a suspension polymerization method was used as a main material powder.
m, flow start temperature 137 ° C, melting point 134 ° C) 300μ
m was passed through the sieve.

To the urethane-based thermoplastic elastomer composition (TPU) powder, a powdery resin composition shown in Table 1 was added as an auxiliary material, and in Examples 4 to 6 and Comparative Example 3, light carbonic acid which was an inorganic fine powder was used. Calcium (MSK-C manufactured by Maruo Calcium Co., Ltd., average particle size: 0.05 μm) was added, and in Example 7 and Comparative Example 4, MMA resin (P
MMA, MP1451 manufactured by Soken Chemical Co., Ltd. Average particle size 0.15
μm) was added in a predetermined amount, and the mixture was mixed with a tumbler for 5 minutes to obtain a thermoplastic urethane composition for powder molding.

Next, in Examples 8 to 17 and Comparative Examples 5 to 8, 40 parts by mass of a polypropylene resin (PP resin), 20 parts by mass of an ethylene-octene copolymer (POE), and 0.3 parts by mass of an organic peroxide Part was dry-blended with a tumbler, and supplied from a raw material supply hopper of a twin-screw extruder (PCM45, manufactured by Ikegai Iron & Steel Co., Ltd.).
The mixture was kneaded at a screw rotation speed of 300 rpm and pelletized. Subsequently, the kneaded pellets, 25 parts by mass of H-SBR, 0.2 parts by mass of phenolic antioxidant, 0.2 parts by mass of phosphite antioxidant, 0.2 parts by mass of hindered amine light stabilizer, and benzotriazole type A dry blend of 0.2 parts by mass of the light stabilizer was supplied from a raw material supply hopper of a similar twin screw extruder, kneaded under the same conditions while injecting process oil from a vent port, and extruded into pellets. Then, a pellet immersed in liquid nitrogen was put into a Turbomill T250-4J (manufactured by Turbo Kogyo) and pulverized to obtain an olefin-based thermoplastic elastomer composition (TPO) powder having a melting point of 149 ° C and an average particle diameter of 200 µm. .

Example 8 was added to the TPO powder as the main material.
In Examples 11 to 13 and Comparative Example 7, light calcium carbonate (MSK-C manufactured by Maruo Calcium Co., Ltd.) was added in Examples 11 to 13 and Comparative Example 7 in Examples 11 to 13 and Comparative Example 7. In Example 14 and Comparative Example 8, an MMA resin (MP1451 manufactured by Soken Chemical Co., Ltd., average particle size: 0.15 μm) was added in Example 14 and Comparative Example 8.
m) was added in a predetermined amount, and mixed by a tumbler for 5 minutes to obtain a thermoplastic olefin composition for powder molding.

Auxiliary material A was composed of 80 parts by mass of thermoplastic urethane (TPU Desmopan, manufactured by Sumitomo Bayer) and 20 parts by mass of silicone oil masterbatch (polypropylene resin composition containing 50% silicone oil) by Labo Plastomill.
(Toyo Seiki Co., Ltd.), frozen and pulverized using liquid nitrogen, and only a 100 μm sieve was collected. This fine powder was added with a predetermined mass part shown in Table 2 with respect to 100 mass parts of TPU powder as a main material to obtain a thermoplastic resin composition for powder molding.

The auxiliary material B is a 12 nylon resin pellet having a melting point of 110 ° C. (melt flow rate (MFR), 100
g / min) 80 parts by mass and silicone oil masterbatch
(Polypropylene resin composition containing 50% silicone oil) A dry blend of 20 parts by mass was screwed at a screw speed of 300 using a twin-screw extruder (PCM45, manufactured by Ikegai Iron & Steel Co., Ltd.) whose cylinder temperature was adjusted to 160 to 200 ° C.
The mixture was kneaded at rpm and extruded into pellets. Further, the powder was freeze-pulverized to obtain a fine powder having an average particle size of 67 μm. This fine powder was added in a predetermined mass part shown in Table 2 with respect to 100 mass parts of TPU powder as a main material to obtain a thermoplastic resin composition for powder molding.

Auxiliary material C is a 12 nylon resin pellet having a melting point of 110 ° C. (melt flow rate (MFR) 100 g).
/ Min) 80 parts by mass and silicone oil masterbatch (low-density polyethylene resin composition containing 50% silicone) 20
Dry blending of parts by mass, cylinder temperature 1
The mixture was kneaded with a twin-screw extruder (PCM45, manufactured by Ikegai Iron and Steel Co., Ltd.) at a temperature of 60 to 200 ° C. at a screw rotation speed of 300 rpm, and extruded into pellets. Further, the mixture was freeze-pulverized to obtain a fine powder having an average particle size of 65 μm. This fine powder was used in Tables 2 to 4 with respect to 100 parts by mass of TPU or TPO powder as the main material.
And a thermoplastic resin composition for powder molding.

Auxiliary material D is composed of 80 parts by mass of a low melting point polypropylene (melt flow rate (MFR) 16 g / min, melting point 137 ° C., CS3650 manufactured by Chisso Corporation) and a silicone oil masterbatch (polypropylene resin composition containing 50% silicone oil). 160-200 ° C by mass
The mixture was kneaded with a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.), and the mixture was frozen and pulverized, and only the fraction passing through a 100 μm sieve was collected. This fine powder was added in a predetermined mass part shown in Table 3 to 100 mass parts of the TPO powder as a main material to obtain a thermoplastic resin composition for powder molding.

The auxiliary material E is a polypropylene having a high melt flowability (melt flow rate (MFR) 400 g / 10
Min, manufactured by Montell, HH-441, melting point 145 ° C) 70
Laboplast obtained by controlling the temperature of 160 parts by mass of a silicone oil masterbatch (polypropylene resin composition containing 50% silicone oil) to 10 parts by mass of a hydrogenated block copolymer (Taftec L515, manufactured by Asahi Kasei Corporation) to 160 parts by mass. After kneading with a mill (manufactured by Toyo Seiki Co., Ltd.) and pulverization by freezing, only a portion passing through a 100 μm sieve was collected. This fine powder was added with a predetermined mass part shown in Table 3 to 100 mass parts of TPO powder as a main material to obtain a thermoplastic resin composition for powder molding.

In Comparative Examples 2 and 6, as the auxiliary material F,
Polyamide resin (Diamid X7341, melting point 120 ° C
An average particle size of 40 μm) was prepared, and a predetermined mass part shown in Tables 2 and 3 was added to 100 mass parts of the TPU or TPO powder as a main material to obtain a thermoplastic resin composition for powder molding. still,
The auxiliary material F does not contain silicone oil. The composition of the auxiliary materials A to F is shown in the table.

[0045]

[Table 1]

As for the powder molding method, a 150 mm × 150 mm × 3 mm plate having a grained pattern is heated to a predetermined temperature in an oven, and the powder for the outer layer is placed on the plate for about 8 mm.
After the powder was not melted and adhered, the powder was heated for 60 seconds in an oven adjusted to 300 ° C., cooled, and then the outer layer having a thickness of 0.9 mm was released. .

With respect to the method of measuring the release strength, powder molding was performed continuously for 10 sheets by the method described above, the molded sheet surface was cut into a width of 60 mm, and the release strength was measured using a spring. The maximum value and the minimum value of the measured values were averaged, and the average release strength (N / 60 mm) was calculated. Then, the steps of molding and peeling were repeated, and the average release strength when stability was reached was defined as release strength.

The obtained molded skin was used as a sample for pinhole evaluation. Confirmation of the pinhole state of the epidermis
The pinhole evaluation sample was magnified with a 15-fold loupe, and the following five-stage evaluation was performed by visual judgment. 1: Pinholes are hardly seen (small pinhole size) 2: Pinholes are slightly seen (small pinhole size) 3: Pinholes are slightly visible visually (medium pinhole size) 4: Pinholes are small 5: Pinholes can be visually confirmed, and there are many (pinhole size is large). Evaluation is performed with n = 3, and the obtained evaluation values are averaged. Pinhole generation evaluation.

Regarding the tensile properties, the skin obtained by powder molding was punched out with a JIS No. 3 dumbbell and JIS K62.
According to No. 51, the tensile strength and the tensile elongation were measured at a tensile speed of 200 mm / min.

[0050]

[Table 2]

[0051]

[Table 3]

From the results shown in Tables 2 and 3, the release strength was reduced by adding an auxiliary material to the thermoplastic resin composition powder.
Further, it can be seen that the pinhole is also reduced. On the other hand,
In Comparative Examples 1 to 4 in which the auxiliary material was not blended, it was difficult to release, and in Comparative Examples 5 to 8, although release was possible, the release strength showed a large value. In addition, the pinhole occurrence rate was high in Comparative Example 1, and in Comparative Examples 3, 4, 7, and 8, even when light calcium carbonate or MMA resin was blended, the pinhole occurrence rates were compared with those of Examples 4 to 7, 11 to 14. Then it was expensive. In Comparative Examples 2 and 6 to which the auxiliary material F containing no silicone oil was added, no particular improvement in the releasability was observed.

Examples 10, 15, 16, 17 and Comparative Example 3 Next, the influence of the physical properties when the blending amount of the auxiliary material was changed as shown in Table 4 using TPO powder as the main material was examined. Table 4 shows the results
It is described together.

[0054]

[Table 4]

As a result of examining the compounding amount of the auxiliary material, in Example 17 in which 20 parts by weight of the auxiliary material was added, the pinhole occurrence state and the mold release strength were as good as Examples 10, 15, and 16, but It was found that the tensile elongation and tensile strength of the obtained skin were reduced.

The surface scratch resistance of the molded sheet was evaluated by visually observing the trace of the surface rubbed with a nail. As a result, since the example to which the auxiliary material was added had good surface lubricity, the scratch resistance was clearly improved as compared with the comparative example.

[0057]

As described above, according to the present invention, in a thermoplastic resin composition for powder molding mainly comprising a thermoplastic resin composition powder, a resin of the same type as the main material or having good compatibility with the main material is used. 0.1 parts by mass, based on 100 parts by mass of the main material powder, obtained by pulverizing a composition obtained by adding 2 parts by mass or more and less than 30 parts by mass of silicone oil to the average particle size of the main material as an auxiliary material By adding less than 20 parts by mass, powder moldability was good, mold release of the molded body was facilitated, and the obtained molded body had few pinholes and the surface was excellent in scratch resistance. Further, by adding an inorganic or organic fine powder in an amount of not less than 0.02 parts by mass and less than 5.0 parts by mass to the mixture of the main material powder and the auxiliary material, the pinhole defect on the surface is further improved. The body is obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 5/00 CFF C08J 5/00 CFF C08K 3/00 C08K 3/00 // (C08L 101/00 (C08L 101/00 83:04) 83:04) B29K 21:00 B29K 21:00 (72) Inventor Yoshihiro Toda 4-1-1-21 Hamazoedori, Nagata-ku, Kobe-shi, Hyogo F-term (reference) 4F070 AA08 AA13 AA15 AB01 AB08 AB09 AB16 AC75 AC90 AC92 AE01 FA03 FA09 FB03 FB05 FB06 4F071 AA12 AA14X AA15X AA20 AA53 AA75 AA78 AD01 AD02 AE17 AH11 BA01 BB03 BC02 4F205 AA11 AB12 A31AA12A31AA12A31AA12AA13AA12AA12AA12AA12AA12AA12AA12A11 BN032 BN172 BP021 CK021 CK022 CL002 CP033

Claims (9)

[Claims] 1. A thermoplastic resin composition for powder molding mainly comprising a thermoplastic resin composition powder, wherein at least one of the same kind of resin as the main material powder or a resin having good compatibility with the main material powder. A resin selected from one as a main component, and a resin component 100
A resin composition comprising 2 parts by mass or more and less than 30 parts by mass of silicone oil with respect to parts by mass, wherein the resin composition having an average particle size smaller than the average particle size of the main material powder is used as an auxiliary material. A thermoplastic resin composition for powder molding characterized by being blended with a powder. 2. The thermoplastic resin composition for powder molding according to claim 1, wherein the auxiliary material is blended in an amount of 0.1 part by mass or more and less than 20 parts by mass with respect to 100 parts by mass of the main material powder. . 3. The resin as a main component of the auxiliary material has a melting point of 100%.
3. The thermoplastic resin composition for powder molding according to claim 1, wherein the thermoplastic resin composition has a melting point or softening point of the resin of the main material powder which is not lower than ℃. 4. An inorganic or organic fine powder having an average primary particle diameter of 1 μm or less is added in an amount of 0.02 parts by mass based on 100 parts by mass of a thermoplastic resin composition for powder molding in which a main material powder and an auxiliary material are mixed. The thermoplastic resin composition for powder molding according to any one of claims 1 to 3, wherein the thermoplastic resin composition is blended in an amount of less than 5.0 parts by mass. 5. The thermoplastic resin composition for powder molding according to claim 1, wherein the main material powder is a thermoplastic elastomer composition. 6. The powder molding heat according to claim 5, wherein the main material powder is a urethane-based thermoplastic elastomer composition, and the main component of the auxiliary material is selected from at least one of nylon 12 and thermoplastic urethane. Plastic resin composition. 7. The main material powder is an olefin-based thermoplastic elastomer composition, and the main component of the auxiliary material is polypropylene, and the polypropylene is selected from at least one of a matrix thermoplastic elastomer composition.
The thermoplastic resin composition for powder molding according to the above. 8. The powder molding composition according to claim 7, wherein the polyolefin-based thermoplastic elastomer composition is a thermoplastic elastomer composition containing at least a polypropylene resin, a hydrogenated styrene-butadiene rubber, and an ethylene / α-olefin block copolymer. Thermoplastic resin composition. 9. A molded product obtained by subjecting the thermoplastic resin composition for powder molding according to claim 1 to powder molding.